Kong Leng Lake

Kong Leng sits in a bowl of limestone north of Thakhek, fed from below rather than by any stream you can see, and the water is the flat green that deep karst pools produce. Nobody locally will give you a depth, and divers who have tried have not found a bottom in the shafts that run off it. The lake is held sacred by the villages around it: the fish are not taken, swimming is restricted to a marked area, and a guide from the village comes with you, which is the arrangement rather than a formality.

What you actually see

• The colour - flat jade-green water, opaque with depth rather than with silt.
• The cliffs - limestone walls dropping straight into the lake on two sides.
• The shallow bay - the one marked area where swimming is allowed.
• The silence - a closed bowl with no outflow noise and very little traffic.

When to go

November to April, when the track in is dry. The colour is strongest under high sun in the middle of the day, which is the opposite of the usual advice. Wet-season access is unreliable.

Honest expectations

The customs here are taken seriously and are the reason the lake is in the condition it is: swim only where you are shown, do not fish, and go with the village guide. The walk in is short but hot. There are no facilities of any kind at the lake.

Nearby

The Thakhek Loop passes nearby, and Kong Lor cave is further north in the same karst.